Preparation of stable, solid, watersoluble, surface-active compositions containing urea and a quaternary ammonium compound



Patented Jan. 29, 1952 2,584,057 ICE PREPARATION OF STABLE, SOLID, WATER- SOLUBLE, SURFACE-ACTIYE COMPOSI- TIONS CONTAINING UREA AND A QUA- TERNARY AMMONIUM COMPOUND Edward C. Sonic and William H.

Sheltmire,

= Niagara Falls, N. Y., assignors to Mathieson Chemical Corporation, a. corporation of Virginia No Drawing. -Application March 4, 1948,

Serial No. 13,085

7 Claims.

This invention relates to improvements in granular, water-soluble, surface-active compositions containing effective proportions of watersoluble, surface-active quaternary ammonium compounds.

A large number of water-soluble, surface-active quaternary ammonium compounds are known. In general, these compounds are substituted ammonium salts in which all four of the hydrogens of the ammonium radical are substituted by organic radicals at least one of which contains a chain of eight to sixteen carbon atoms. While it is possible to produce such water-soluble, surface-active quaternary ammonium compounds which are solids at ordinary atmospheric temperatures, the cost of the special raw materials required makes the cost of such compounds prohibitive in terms of commercial application. Further, although such compounds may be described as solids," they frequently exhibit an oiliness or greasiness which causes them to agglomerate rapidly when originally flaked or granulated.

For example, cocoanut oil is a low cost raw material for the production of a particularly valuable group of such quaternary ammonium compounds, the distribution in length of the carbon chains of the constituent fatty acids being such that the quaternary ammonium compounds formed by conversion of the mixed fatty acids to amines followed by methylation and reaction with benzyl chloride are unusually effective surface-active and bactericidal agents. However, even when substantially anhydrous, these compounds are normally either an oily liquid or a greasy solid.

Other known water-soluble, surface-active quaternary ammonium compounds include lauryl dimethyl benzyl ammonium chloride, cetyl trimethyl ammonium bromide, heptadecyl trimethyl ammonium chloride, lauryl pyradinium chloride. octadecyl pyridinium bromide, decyl chlorobenzyl diethyl ammonium chloride, undecyl benZyl diethyl ammonium bromide, and the like.

These quaternary ammonium compounds are effective in dilutions of as little as T-s%, 40071 or even .400070, for example in sanitizing vessels and utensils used in connection with food and drink, and are commonly used in aqueous solutions of such concentrations. For this reason, and the further reason that they are conveniently prethese compounds depress the freezing point of their solutions very little, containers in which such aqueous solutions are shipped, stored or handled must be protected against freezing to avoid losses resulting from resultant container damage. Of course, any such solid product must be of the same order of solubility as the quaternary ammonium compound itself if its practical value is to be maintained.

This problem has been recognized for some time and'various expedients for dealing with it have been suggested. Probably the most effective of such proposals has been that of fusing the quaternary ammonium compound with urea. In some proportions, reasonably dry solids can be thus prepared but a fusion temperature upwards of about 110-115 C. is usually required to obtain a homogeneous product and such temperatures initiate a curious decomposition that continues for an indefinite period even after the fusion is solidified and cooled to ordinary atmospheric temperatures. Such decomposition not only involves substantial losses of the effective agent but also renders the product objectionable during handling and in use.

Proposals involving the admixture of some inorganic salt with the quaternary ammonium ccmpound, to take up any water present, have been less than successful for the reason that the diiiiculties involved are not to be solved merely by removing or binding the water present. The product remains an oily or greasy product tending to agglomerate.

This invention relates particularly to improvements in granular, water-soluble, surface-active compositions containing effective proportions of a water-soluble, surface-active quaternary ammonium compound and urea.

A mixture of urea in major proportion and such quaternary ammonium compounds in minor but effective proportion can be fused to produce a homogeneous melt, but the temperature required to obtain a homogeneous fusion from such simple mixtures usually exceeds 1l0-l30 C. and such temperatures initiate the curious decomposition previously mentioned. The decomposition products include ammonia and more odoriferous reaction products and the decomposition reaction. once initiated, continues with evolution of such decomposition products for a long period. This decomposition is not arrested by cooling and solidifying the fusion or melt.

W have discovered that mixtures of urea and 3%-22% by weight on the urea of such watersoluble, surface-active quaternary ammonium com ounds can be heated to temperatures as hi h as l40-150 C. to produce a homo eneous melt without initiating the decompo ition previously mentioned provided a small proportion of a nonoxidizing acid not more volatile than acetic ac d is presentduring fusion and rovided the pronortion of urea does not exceed 95% by weight on The acids we have found particularlyadvan tageous are acetic acid, phosphoric acid and sulfuric acid. of these, we prefer acetic acid. -The proportions required approximate 2%12% by weight on the total of urea and quaternary am-' monium compound. The action of the acidappears to be more complex than simple neutralization of ammoniacal decomposition products. Even with the acid present, such decomposition products are usually evolved during fusion if the temperature much exceeds 115 C. And stability with respect to this decomposition is. .not attained by adding the acid to the product if, during fusion, the decomposition is initiated. Thus, the process of our invention comprises fusing together urea and about 3%-22% by weight on the urea of the water-soluble, surface-active quaternary ammonium compound, at a superatmospheric temperature for example of 110-150 (3., in the presence of about 2%-12% by weight on the total of urea and quaternary ammonium compound of such an acid. Following fusion, the melt is cooled and solidified. The product may be flaked or granulated as it solidifies or the solidified melt may be ground.

The granularproduct of our invention comprises urea, but not more than 95% by weight on the total product of urea, about 3%22% by weight on the urea of a water-soluble, surface-active quaternary ammonium compound and about 2%-12% by weight on the total of urea and quaternary ammonium compound of, for example, acetic acid,

phosphoric acid or-sulfuric acid, and it may contain as much as 20% by weight on the total of urea, quaternary ammonium compound and acid of water. The quaternary ammonium compound may be supplied to the fusion operation, for example, as an aqueous solution containing 50% by weight of the quaternary ammonium compound.

The direct product of such fusion, will, within the stated limits, be stable solids. Or, the quaternary ammonium compound may be dehydrated, partially or to substantially anhydrous condition before being supplied to the fusion operation. Again, the melt produced by fusing a concentrated aqueous solution of the quaternary ammonium compound with the urea and sodium acetate may be dehydrated after solidification. In any dehydration of the quaternary ammonium compound or products containing them, temperatures involving decomposition are to be avoided. One particularly advantageous product of our invention comprises urea, but not more than about 95% by weight on the total product of urea, about 3%-22% by weight on the urea of a water-soluble, surface-active uaternary ammonium compound, about 2%12% by weight on the total of urea and quaternary ammonium compound of, for example, acetic acid, phosphoric acid or sulfuric acid, and about 10%-20% by weight on the total of urea, quaternary ammonium compound and acid of water. For many purposes, however, the proportion of water may be 4%-1% or less.

The practice and products of our invention will be illustrated by the following examples. In these examples, all parts are parts by weight.

Example I A water-soluble, surface-active quaternary ammonium compound was derived from cocoanut oil fatty acids, by conventional processing, by conversion of the fatty acids to the correspondin cocoa amines, methylatlon to form dimethyl cocoa amines and treatment with benzyl chloride to produce cocoa dimethyl benzyl ammonium chlo-' ride in the form of a 50% by weight aqueous solution.

A series of compositions were prepared each containing 20 parts of this aqueous-solution, proportions of glacial acetic acid varying from nothing to ten parts and that proportion of urea required to bring the total to 100 parts and each was fused to a clear homogeneous melt at a tempera- Proportions Ammoniacal Decomposition Quaternary Product Urea Ammonium Wutcr d Evolved Compounds 10 l0 0 Yes. 70 ll) l0 10 N0. 75 ll) 10 '1 No. 77' l0 10 i N0. 78 lll l0 2 N0. 78. 5 l0 l0 1 5 Yes 79 10 10 1 Yes Example II The procedure was the same as in the first example except that substantially all. vf the water had been removed from the quaternary ammonium compound by vacuum dehydration before it was supplied to the fusion. The results were as follows:

i Proportions Ammoniacal Decomposition Quaternary A coup Product Urea Ammonium A Evolved i I Compounds c l i 10 0 Yes. i 85 10 5 No. 87 10 3 No. i 88 10 2 No.

88 5 10 1.5 Slight. so I 10 1 Slight.

Example III 20 parts of an aqueous solution containing 50 parts by weight of lauryl pyridinium chloride, '75 parts of urea and 5 parts of 'syrupy phosphoric acid were fused to a clear homogeneous melt at a temperature of -140 C. and the fusion was cooled and solidified. The solid product did not evolve ammoniacal decomposition products.

Other materials may be compounded with the product of our invention. For example, other surface-active materials such as sodium lauryl sulfate, potassium mono-naphthalene sulfonate and alkylaryl :polyetheralcohols, and alkylol amides, sodium carbonate, sodium bicarbonate, normal and acid orthophosphates, polyphosphates such as triphosphate and tetraphosphate, polymetaphosphates. pyrophosphates and borates including borax may be included in the composition.

The process of our invention is, in a broader aspect, applicable to the production of homogeneous, solid products comprising urea and such water-soluble, surface-active quaternary ammonium compounds in cast shapes, for example, rather than in granular form. If the product is not to be granular, the proportions of quaternary ammonium compound on the urea may be varied over wider limits than those previously stated for granular products. For the production of such non-granular solid products, the proportion of the quaternary ammonium compound may range from 3% to 45% by weight on the urea.

We claim:

1. A method of compounding stable, solid, water-soluble, surface-active compositions which comprises fusing together the materials listed below in proportions within the indicated ranges by weight: a major proportion of urea in an amount not exceeding 95% of the total composition, 3% to 45% based on the weight of the urea of a water-soluble, surface-active quaternary ammonium salt in which all four hydrogens of the ammonium radical are substituted by ,organic radicals at least one of which contains a chain of 8 to 16 carbon atoms and 2%l2% based on the total weight of the urea and the quaternary ammonium compound of an acid selected from the group consisting of glacial acetic acid, syrupy phosphoric acid and concentrated sulfuric acid, at superatmospheric temperature of about 110-150 C. and cooling and solidifying the resulting melt.

2. A method of compounding stable, solid, water-soluble, surface-active compositions which comprises fusing together the materials listed below in proportions within the indicated ranges by weight: a major proportion of urea in an amount not exceeding 95% of the total composition, 3% to 22% based on the weight of the urea of a water-soluble, surface-active quaternary ammonium salt in which all four hydrogens of the ammonium radical are substituted by organic radicals at least one of which contains a chain of 8 to 16 carbon atoms and 2%l2% based on the total weight of the urea and the quaternary ammonium compound of glacial acetic acid, at superatmospheric temperature of about 110-150 C. and cooling and solidifying the re- Sulting melt.

3. A method of compounding stable, solid, water-soluble, surface-active compositions which comprises fusing together the materials listed below in proportions within the indicated ranges by weight: a major proportion of urea in an amount not exceeding 95% of the total composition, 3% to 22% based on the weight of the urea of a water-soluble, surface-active quaternary ammonium salt in which all four hydrogens of the ammonium radical are substituted by organic radicals at least one of which contains a chain of 8 to 16 carbon atoms and 2%l2% based on the total weight of the urea and the quaternary ammonium compound of syrupy phosphoric acid, at superatmospheric temperature of about l10-150 C. and cooling and solidifying the resulting melt.

4. A method of compounding stable. solid, water-soluble, surface-active compositions which comprises fusing together the materials listed below in proportions within the indicated ranges by weight a major proportion of urea in an amount not exceeding 95% of the total composition, 3% to 22% based on the weight of the urea of a water-soluble, surface-active quaternary ammonium salt in which all four hydrogens of the ammonium radical are substituted by organic radicals at least one of which contains a chain of 8 to 16 carbon atoms and 2%l2% based on the total weight of the urea and the quaternary ammonium compound of concentrated sulfuric acid, at superatmospheric temperature of about 1l0-150 C. and cooling and solidifying the resulting melt.

5. A method of compounding stable, solid, water-soluble, surface-active compositions which comprises fusing together the materials listed below in proportions within the indicated ranges by weight: a major proportion of urea in an amount not exceeding 95% of the total composition, 3% to 45% based on the weight of the urea of a water-soluble, surface-active quaternary ammonium salt in which all four hydrogens of the ammonium radical are substituted by organic radicals at least one of which contains a chain of 8 to 16 carbon atoms and 2%l2% based on the total weight of the urea and the quaternary ammonium compound of glacial acetic acid at superatmospheric temperature of about 110- 150 C. and cooling and solidifying the resulting melt. 4

6. A method of compounding stable, solid, water-soluble, surface-active compositions which comprises fusing together the materials listed below in proportions within the indicated ranges by weight: a major proportion of urea in an amount not exceeding 95% of the total composition, 3% to 45% based on the weight of the urea of a water-soluble, surface-active quaternary ammonium salt in which all four hydrogens of the ammonium radical are substituted by organic radicals at least one of which contains a chain of 8 to 16 carbon atoms and 2%l2% based on the total weight of the urea and the quaternary ammonium compound of syrupy phosphoric acid, at superatmospheric temperature of about 110-150 C. and cooling and solidifying the resuiting melt.

7. A method of compounding solid, watersoluble, surface-active compositions which comprises fusing together the materials listed below in proportions within the indicated ranges by a, weight: a major proportion of urea in an amount EDWARD c. SOULE. WILLIAM H. sm'mms.

REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN. ra'ranrs Country Number Date Great Britain liar. 6, 1986 

1. A METHOD OF COMPOUNDING STABLE, SOLID, WATER-SOLUBLE, SURFACE-ACTIVE COMPOSITIONS WHICH COMPRISES FUSING TOGETHER THE MATERIALS LISTED BELOW IN PROPORTIONS WITHIN THE INDICATED RANGES BY WEIGHT: A MAJOR PROPORTION OF UREA IN AN AMOUNT NOT EXCEEDING 95% OF THE TOTAL COMPOSITION, 3% TO 45% BASED ON THE WEIGHT OF THE UREA OF A WATER-SOLUBLE, SURFACE-ACTIVE QUATERNARY AMMONIUM SALT IN WHICH ALL FOUR HYDROGENS OF THE AMMONIUM RADICAL ARE SUBSTITUTED BY ORGANIC RADICALS AT LEAST ONE OF WHICH CONTAINS A CHAIN OF 8 TO 16 CARBON ATOMS AND 2%-12% BASED ON THE TOTAL WEIGHT OF THE UREA AND THE QUATERNARY AMMONIUM COMPOUND OF AN ACID SELECTED FROM THE GROUP CONSISTING OF GLACIAL ACETIC ACID, SYRUPY PHOSPHORIC ACID AND CONCENTRATED SULFURIC ACID, AT SUPERATMOSPHERIC TEMPERATURE OF ABOUT 110*-150* C. AND COOLING AND SOLIDIFYING THE RESULTING MELT. 